The process energy consumed in the distillation of bio-products often constitutes the largest energy requirement in the production life cycle of those products. Distillation systems are designed to meet a number of requirements appropriate to the priorities existing when design and investment decisions are made. First-generation distillation systems were implemented when simplicity was highly prized and environmental concerns related to energy usage were largely relegated to minimizing associated hazardous emissions. Today, policies and regulatory initiatives targeting the reduction of greenhouse gas emissions are impacting consumers and producers of energy, creating incentives for improving energy efficiency and minimizing environmental footprints.
Examples of regulation impacting energy consumers and producers include California's Low Carbon Fuel Standard (LCFS) and the U.S. EPA's Clean Power Plan. The LCFS models life cycle fuel pathways to assign a Carbon Intensity (CI) to fuels that reflects a fuel's carbon dioxide emissions. A fuel producer's pathway, reflecting the CI for their process, generates credits or requires the purchase of credits from other producers to meet California's CI targets. These credits are traded on an exchange that establishes their value and permits monetization by producers. Improvements in process energy efficiency are directly rewarded through the LCFS system, incentivizing energy efficiency investments. This system, and similar systems under consideration by governmental authorities, directly reward producers for reducing their energy requirements, even when low energy prices provide little or no incentive to make such investments.
Bio-fermentation products, which include biofuels, are the result of the investment of energy by growing a biological raw material which is then converted by chemical processing to a purified liquid fuel, with each step requiring energy-intensive stages which include distillation. Conventional, first-generation methods employed at a bio-distillery plant expend significant energy in distillation. The inefficiency of these methods negatively impacts producer economics as well as the environmental footprint ascribed to the process.
Improvements in overall energy efficiency and optimization are still needed commercially for new or existing distilleries, or new or existing biorefineries employing distillation.